lib/percheron/actions/build.rb in percheron-0.7.11 vs lib/percheron/actions/build.rb in percheron-0.7.12

@@ -10,35 +10,68 @@
         @exec_scripts = exec_scripts
       end
 
       def execute!
         results = []
-        results << build! if unit.buildable?
+        if unit.buildable?
+          results << write_out_temp_dockerfile!
+          results << build!
+        end
         results.compact.empty? ? nil : unit
       end
 
       private
 
         attr_reader :unit, :nocache, :exec_scripts
         alias_method :exec_scripts?, :exec_scripts
 
         def options
           {
-            'dockerfile'  => unit.dockerfile.basename.to_s,
+            'dockerfile'  => dockerfile,
             't'           => unit.image_name,
             'forcerm'     => true,
             'nocache'     => nocache
           }
         end
 
+        def dockerfile
+          temp_dockerfile.basename.to_s
+        end
+
+        def temp_dockerfile
+          @temp_dockerfile ||= Pathname.new(temp_dockerfile_name)
+        end
+
+        def temp_dockerfile_name
+          @temp_dockerfile_name ||= begin
+            '%s/%s.%s' % [
+              unit.dockerfile.expand_path.dirname.to_s,
+              unit.dockerfile.basename.to_s,
+              SecureRandom.urlsafe_base64
+            ]
+          end
+        end
+
+        def write_out_temp_dockerfile!
+          options = { 'secrets' => Config.secrets }
+          content = Liquid::Template.parse(unit.dockerfile.read).render(options)
+          File.open(temp_dockerfile, 'w') { |f| f.write(content) }
+        end
+
+        def remove_temp_dockerfile!
+          temp_dockerfile.delete
+        end
+
         def build!
           in_working_directory(base_dir) do
             execute_pre_build_scripts!
             $logger.info "Building '#{unit.image_name}' image"
             Connection.perform(Docker::Image, :build_from_dir, base_dir, options) do |out|
               $logger.debug '%s' % [ out.strip ]
             end
           end
+        ensure
+          remove_temp_dockerfile!
         end
 
         def execute_pre_build_scripts!
           return nil if !exec_scripts? && unit.pre_build_scripts.empty?
           ExecLocal.new(unit, unit.pre_build_scripts, 'PRE build').execute!